This invention relates to ground working devices, particularly snow grooming devices. More specifically, this invention relates to tillers for use with snow grooming vehicles for ski slopes.
Ground working devices have long been used in agriculture to break up and till earth. Such devices, known as tillers, typically include a trailing assembly that has a rotating ground loosening unit and a smoothing or leveling board. The loosening unit can be subdivided into subassemblies connected by joint(s) to accommodate the changing contours of the ground.
This general concept has been adopted and modified to groom snow, especially ski slopes. Snow making and snow grooming has become an essential part of any successful ski center due to increased skier traffic, longer ski seasons, and variable weather conditions. As a result, snow groomers are becoming more sophisticated. Typical snow grooming vehicles are tracked vehicles, which provide traction across the snow and up and down hills. These vehicles are equipped with a number of attachments or devices to help in the snow grooming process.
Generally, a tracked snow vehicle has an inverted V-shaped or U-shaped plow on the front of the vehicle that collects snow from areas where there is too much and moves it to areas which are worn. The front implement can also rip up icy and encrusted slopes to create or renew trails and remove glacier surface ice. The front implement can include a toothed bar that is lowered by a pivoting ram to break up hard, icy slopes into large lumps. The tracks of the vehicle assist in breaking up the lumps. Attached to the rear of the vehicle is a snow tiller that grinds the lumps and surface and then smoothes the surface of the snow to restore it to skiing condition.
Snow tillers are frequently equipped with a drum formed as a rotating blade and a finishing member that trails behind the rotor. A snow chamber is formed immediately behind the drum under and behind the finishing member to hold a volume of snow so that it can be worked more extensively by the tiller. Variations in volume and configuration of the snow chamber can be provided during operation of the snow groomer according to U.S. Pat. No. 5,067,263, to provide additional control over the tiller performance. The finishing member is usually a flexible mat or mats having grooved finishing elements provided at the rear of the tiller assembly to provide the final snow surface conditioning by smoothing or, alternatively, to provide a xe2x80x9ccorduroyxe2x80x9d texture to the surface of the tilled snow.
Currently, snow tillers can be provided as multisection tillers (with various subassemblies), which typically operate in a xe2x80x9cfloatingxe2x80x9d mode or in a xe2x80x9clockedxe2x80x9d mode. In the floating mode, each independent tiller subassembly is permitted to float over the snow surface so that it can change orientation corresponding to the terrain. In the locked mode, each tiller subassembly is mechanically locked into a particular orientation.
Because of differing snow conditions, the desired for particular snow profiles, and the presence of obstacles (particularly in low snow conditions), present day tillers have been found to suffer serious disadvantages. For example, it is sometimes desirable to create concave and convex snow profiles to create moguls and tubes on a ski slope. Unfortunately, when the tiller subassemblies of prior art tillers are locked into position to provide a desired snow profile, they are unable to move away from obstacles and become much more vulnerable to damage and can produce degraded profiles. Also, the locked profiles cannot accommodate the natural contours of the slope. So, instead of forming the desired contour in the snow surface, the surface may become gouged or otherwise unacceptable due to the inflexibility of the tiller. Additionally, the weight of the vehicle and the weight of the tiller tend to flatten the terrain.
Therefore, there is a need for a more flexible assembly in which the contour of the tiller can be selectively adjusted and controlled. There is also a need for an assembly that provides the operator with selective control of the snow tiller to vary the desired groomed profile.
An aspect of this invention is to provide a tiller provided with tiller subassemblies that can be operated in a xe2x80x9cfloatingxe2x80x9d mode or in a releasable xe2x80x9clockedxe2x80x9d mode. The releasable locked mode function can selectively allow, under certain conditions, the tiller subassemblies to enter a xe2x80x9cfloatingxe2x80x9d mode to reduce the possibility of damage to the tiller and then return the xe2x80x9creleasedxe2x80x9d tiller subassembly to its preselected orientation to provide a more consistent snow profile.
Another aspect of this invention provides a tiller with tiller subassemblies that can be configured in a variety of orientations in the releasable xe2x80x9clockedxe2x80x9d mode to create a corresponding variety of snow profiles.
A further aspect of this invention can provide variations of electrical control systems for adjusting the relative orientation of the tiller subassemblies to provide and maintain the profile selected by the operator, both manually and automatically.
An additional aspect of this invention comprises a simple hydraulic arrangement for adjusting the tiller, which can reduce manufacturing and maintenance costs.
Embodiments of this invention provide a snow tiller device adapted to be pulled by a power source comprising a multisection tiller assembly having a plurality of tiller subassemblies and tiller elements. A positioning mechanism selectively positions the tiller subassemblies relative to one another. A controller coupled to the positioning mechanism selectively maintains the desired positioning to enable the operator to create a variety of snow profiles according to conditions and intended use. Maintenance of the profile can be accomplished manually or automatically.
The invention can also include the combination of a selectively controlled tiller with a vehicle.
The method of controlling the tiller profile including selectively positioning the tiller subassemblies and controlling the positioning is also encompassed by the invention.
It is to be understood that the invention described herein can be varied in a number of ways and is not restricted to the particular embodiments described herein. The invention is intended to generally include a variety of equipment arrangements wherein the relative orientation of two or more tiller subassemblies or tiller elements can be selectively set and controlled to form a variety of different profiles.